Source:http://linkedlifedata.com/resource/umls/id/C0182038
UMD: Ophthalmic devices designed to facilitate gaze fixation on a fixed and/or moving light. These instruments usually consist of a mount with a headrest and a light source on which the patient fixes his or her gaze; the light source can be moved relative to the head rest. Ophthalmic fixation units are used mainly for diagnosis and treatment of eye conditions while the patient's gaze is fixed.